similar to: Standard errors in regression models with interactions terms

I want to use the caret package to train linear models. I want to compare these models when using different degrees (aka degrees of interaction). This is possible for the 'earth' method (using the '.degree' parameter) but I found no possibility of customizing the degree for the 'lm' method. This might be due to the fact that the basic 'lm' function does not support

Hi Everyone, I often use the 'safe prediction' feature available through glm(). Now, I'm at a situation where I must use biglm:::bigglm. ## begin example library(splines) library(biglm) ff <- log(Volume)~ns(log(Girth), df=5) fit.glm <- glm(ff, data=trees) fit.biglm <- bigglm(ff, data=trees) predict(fit.glm, newdata=data.frame(Girth=2:5)) ## -1.3161465 -0.2975659

I want to use the caret package and found out about the timingSamps obtion to obtain the time which is needed to predict results. But, as soon as I set a value for this option, the whole model generation fails. Check this example: ------------------------- library(caret) tc=trainControl(method='LGOCV', timingSamps=10) tcWithout=trainControl(method='LGOCV')

Hy, I got the following problem when trying to build a rpart model and using everything but LOOCV. Originally, I wanted to used k-fold partitioning, but every partitioning except LOOCV throws the following warning: ---- Warning message: In nominalTrainWorkflow(dat = trainData, info = trainInfo, method = method, : There were missing values in resampled performance measures. ----- Below are some

I am using lme4 to fit a mixed effects model to my data. I have a significant interaction between two variables. My question is what is the correct way to get p-values for single terms involved in that interaction. I have been using stepwise backwards deletion and model comparisons to get p-values,and refitting the model using a REML approach to get estimates.However, presumably to get the p

Yes, I am a newbie at R, but it is not the complex commands in R that have me baffled, but simple data commands. For example, why does something like: > plot(Girth ~ Height) *not* work after a command that allegedly loads the data: > data(trees) with the error message: Error in eval(expr, envir, enclos) : Object "Girth" not found but does work after the command: >

Hi I have a problem accessing an array field in a Postgresql database. Here is the table definition. View "neil.flashing_codes" Column | Type | Modifiers -------------+-----------------------+----------- code | character varying(10) | description | text | folds | integer[] | View definition: SELECT

I am trying to run an ancova and am having trouble setting it up properly. I have nearly 10,000 measurements of fish length, girth and stage of sexual development. I am suspicious that the stage of development is affecting the length (as they get full of eggs they get more round and are more difficult to measure and measure shorter). My data looks somethign like this: Length girth stage 40 50

Dear all, The 'make check' step fails for the pacakge mva on IBM AIX. The tail of the Rout log file looks like: > for(factors in 2:4) print(update(Harman23.FA, factors = factors)) Call: factanal(factors = factors, covmat = Harman23.cor) Uniquenesses: height arm.span forearm lower.leg weight 0.170 0.107 0.166

Hi all, first of all, I'm not an expert on R, I'm still learning, so sorry if this is a stupid question... I have a large dataset that is to big for my computer memory, and I found quite useful the package biglm. Now everything is working perfectly. But if I want the residuals, how I can do it? Let's say that we are running the example: > data(trees)>

The "earth" package is now available on CRAN. Earth builds models using Friedman's MARS. Earth's principal advantages over the existing function mda::mars are that it is much faster and provides plotting and printing methods. The general purpose model plotting function "plotmo" may also be useful to people who are not interested in earth itself. Example: > a

The "earth" package is now available on CRAN. Earth builds models using Friedman's MARS. Earth's principal advantages over the existing function mda::mars are that it is much faster and provides plotting and printing methods. The general purpose model plotting function "plotmo" may also be useful to people who are not interested in earth itself. Example: > a

I tried to run the following example from section 4.1.4 of the "Scatterplot3d - an R package for Visualizing Multivariate Data" vignette and got an error on the part that plots the regression plane: > library(scatterplot3d) > data(trees) > s3d <- scatterplot3d(trees, type = "h", color = "blue", + angle = 55, scale.y = 0.7, pch = 16, main = "Adding

Dear R helpers, I have a 3D scatter plot that I have generated from scatterplot3d (which looks great- thanks!) and I can see that the points in my graph fall in a plane. Following the example 5 from 3D scatter plot (below) I have fitted a regression plane. Now what I would like to do is a rotation so that my new co-ordinate system is about the fitted plane (by finding the normal to the plane

Hi all, I'm an R newbie, I did this script to create a scatterplot using the "tree" matrix from "datasets" package: library('datasets') with(trees, { plot(Height, Volume, pch=3, xlab="Height", ylab="Volume") symbols(Height, Volume, circles=Girth/12, fg="grey", inches=FALSE, add=FALSE) } ) I'd like to use the column Named

Problem: I am sorting through model selection process for first time and want to make sure that I have used glm, stepAIC, and update correctly. Something is strange because I get a different result between: 1) a glm of 12 predictor variables followed by a stepAIC where all interactions are considered and then an update to remove one specific interaction. vs. 2) entering all the terms

Hi All. I'd like to programm a 4 dimensional chart in R. Acctually I wanted to solve that problem in Excel cause I had the data there. Here is a link of my actual problem description (there are some chart pictures as well).... http://www.mrexcel.com/board2/viewtopic.php?t=187336&highlight=stacked+column because I still couldn't solve that problem I came to R. The chart should be

I'm having a problem with rgl.snapshot. If I run the following code *once* and *once only*, all is well. data(trees) attach(trees) plot3d(Height, Girth, Volume, type='s') rgl.snapshot("/home/user/pic.png", fmt="png", top=TRUE ) And the pic.png looks right. But if I try to rerun rgl.snapshot anytime again in this session, the file pic.png still outputs but is

igraph is a package for graphs and networks. It has a C core and uses a simple and fast graph representation allowing millions of vertices and edges. NEW FEATURES: - We use the ARPACK library for graph related eigenvalue problems, like Page Rank calculation, Kleinberg's hub and authority scores, eigenvector centrality, etc. There is also a generic interface if someone wants to use

igraph is a package for graphs and networks. It has a C core and uses a simple and fast graph representation allowing millions of vertices and edges. NEW FEATURES: - We use the ARPACK library for graph related eigenvalue problems, like Page Rank calculation, Kleinberg's hub and authority scores, eigenvector centrality, etc. There is also a generic interface if someone wants to use